<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<meta name="viewport" content="width=device-width,initial-scale=1.0">
		<style>
		  *{padding: 0;margin: 0;}
		  html{
		    font-size: 20px;
		  }
		  body{
		    font-size: 0.5rem;
		  }
		  .box{
		    width: 24rem;
		    background: red;
		    height: 2rem;
		  }
		  .b_cont1{
		    width: 12rem;
		    background: blue;
		    height: 1rem;
		    float: left;
		  }
		  .b_cont2{
		    width: 12rem;
		    background: yellow;
		    height: 1rem;
		    float: right;
		  }
		</style>
	</head>
	<body>
	  <div class="box">
	    <div class="b_cont1">你是傻叉</div>
	    <div class="b_cont2"></div>
	  </div>
	</body>
	<script>
	  document.documentElement.style.fontSize = document.documentElement.clientWidth / 24 + 'px';
	</script>
</html>
